Door latch mechanism

ABSTRACT

An automotive door latch mechanism comprising a rotatable latch bolt in the form of a fork and a bolt-supporting shaft and a striker pin for engagement by said latch bolt, said mechanism including a cancelling lever to release engagement between the striker pin and the latch bolt, an open lever for actuating the cancelling lever and a locking lever for preventing the cancelling lever from releasing the engagement between the striker pin and the latch bolt.

United States Patent n 1 Yoshimura 1 Oct. 23, 1973 000 LATCH MECHANISM[75] Inventor:

[73] Assignee: Aisin Seiki Kabushiki Kaisha,

Kariya City, Japan Noboru Yoshimura, Toyota, Japan [22] Filed: June27,1972

21 Appl. No.: 266,548

Related U.S. Application Data [62] Division of Ser. No. 75,848, Sept.28, 1970, Pat. No.

[30] Foreign Application Priority Data Oct. 4, 1969 Japan 44/94742 [52]U.S. Cl. 292/216, 292/D1G. 26 [51] Int. Cl. E05c 3/26 [58] Field ofSearch 292/198, 216, 280, 292/D1G. 25,'DIG. 26

[56] References Cited UNITED STATES PATENTS 2,644,707 7/1953 Dall292/216 Dingman et a1. 292/280 Kanaoka et al 292/216 PrimaryExaminerRichard E. Moore Attorney-Pierce, Scheffler & Parker [57]ABSTRACT An automotive door latch mechanism comprising a rotatable latchbolt in the form of a fork and a boltsupporting shaft and a striker pinfor engagement by said latch bolt, said mechanism including a cancellinglever to release engagement between the striker pin and the latch bolt,an open lever for actuating the canceiling lever and a locking lever forpreventing the cancelling lever from releasing the engagement betweenthe striker pin and the latch bolt.

5 Claims, 9 Drawing Figures 1 DGQR LATCII MECHANISM This is a division,of application Ser. No. 75,848 tiled Sept. 28, 1970 now U.S. Pat. No.3,705,738. I

This invention relates to a door latch mechanism for an automotivevehicle, and more particularly to a door latch mechanism including alatch bolt in the form of a rotatable fork, i.e. the fork-type latchmechanism.

In the field of automotive door latch mechanisms it is desired toprovide a possibility for performing the following multipurposefunctions:

1. When the vehicle door has been closed, the door is kept in its closedposition without being lowered relative to a stationary member of thevehicle such as a center pillar.

2. When the vehicle is in its running condition, the

door latch mechanism produces no noises and rattles due to the bumpingof the vehicle along the rough road.

3. When the vehicle door has been closed, the door can be maintainedinits closed condition even when a heavy force to open the door such as aheavy shock in emergency is applied thereto.

4. To provide a possibility of lock cancelling operation which meansthat when a person depresses the inside door locking knob and thenleaves the vehicle and closes the door, the once'latched door will beautomatically released.

5. To provide a possibility of keyless lock operation which means thatunder the same conditions as is described above the door latch mechanismcan be released by closing the door with its outside handle beingintentionally kept in itsdoor open position.

The main object of the invention is to provide anautomotive door latchmechanism adapted for performing the aforementioned various and desirousfunctions.

Another object of the invention is to provide a door latch mechanismwhich is characterized by its simplicity and compactness in constructionand which is relatively small in size, economical to manufacturecomparatively quiet in operation and efficient in use.

The door latch mechanism according to' the present invention comprises,

l. a bolt-supporting shaft, said shaft being enlarged at a part which isengageable with and slightly raised by the striker on the stationarymember of the vehicle whereby the lowering of doorrelative to the latterwill be prevented;

2. a rotatable striker-pressing member, said member being provided witha resilient means for urging said member to press resiliently againstthe striker in its fully-latched position whereby no noises or rattlesof the latch mechanism will be produced;

3. a latch base plate fixed to the door and a hanger plate to which theheavy longitudinally acting force to destroy the door latch mechanismmay be applied, said hanger plate being integral with said base platewhereby the said heavy force may not destroy the latch mechanism;

7 4. a rotatable pawl to engage the latch bolt for performing the doorlocking operation, the engagement point of the pawl and latch beingpositioned in the same plane as that of the striker and latch boltwhereby no twisting force is applied on the pawl, thus the engagement ofthe pawl and latch bolt is kept in safety even when a heavy laterallyacting shock may be applied; (It should be recognized that in theconventional door latch mechanism the ratchet to engage the pawl hasbeen rotatably mounted on the bolt-supporting shaft on the back of thebase plate relative to the latch bolt so that when the laterally actingshock is applied to the vehicle the engagement of the ratchet and pawlis liable to be released.)

5. an open lever operatively connected both to the inside open handleand to the inside open button, and a locking lever operatively connectedboth to the outside key means and to the inside lock button, both saidlevers being adapted to accomplish the above-mentioned lock cancellingoperation and keyless locking operation.

The invention will now be further described with reference to theaccompanying drawings which illustrate, by way of example, a door latchmechanism in accordance with the invention.

In the drawings: 1

FIG. I is a plan view of a conventional striker alone; FIG. 2 is a sideelevational view of the striker of FIG.

FIG. 3 is a plan view partly in section showing the inside of the doorlatch mechanism according to this invention in the fully latchedposition FIG. 3a is a cross-sectional view taken along line 3A3A of FIG.3.

FIG. 4 is a vertical cross sectional view taken on the plane indicatedby the line IV-IV of FIG. 3;

FIG. 5 is a side elevation in the direction of the arrow V in FIG. 3;

FIG. 6 is a view similar to FIG. 3, but in the unlatched condition;

FIG. 7 is an external face view of the latch mechanism;

FIG. 8 is an internal view opposite to that of FIG. 7; and

FIG. 9 is a view similar to FIG. 3, but showing a modi fied form of thelatch mechanism.

Referring to the drawings, the numeral 10 denotes generally aconventional keeper or striker which is fixedly attached to a certainstationary member of the automotive vehicle. The striker It comprises astriker plate II and a U-shaped pin 12 fitted integrally therewith.

A door latch mechanism 13 is fixedly attached to each door of thevehicle to cooperate with the striker It). The mechanism I3 comprises adoor latch base 14 which is secured to the door and a hanger plate l5which is made integrally with the base plate 14 by stamping andprotruded therefrom outside of the door in a manner of so-calledplant-on type. A cover plate M is secured to the base plate M. Thehanger plate 15 and cover plate dI mount rigidly two separate shaft I6and I7. A rotatable fork-shaped latch or bolt 18 is made integrally withthe former shaft I6 while a swinging detent or pawl 19 is mounted on thelatter shaft 17.. The latch bolt 18 is formed with a recess 26 whichstraddles over the striker pin 12, and further with first and secondratchet teeth 21 and 22, respectively, either thereof being adapted forengagement with tooth 23 formed on the pawl ISB.

The numeral .24 indicates a coil spring which is mounted on and betweenan inwardly projecting rod or pin 25 integral with the bolt I8 and anoutward projection 26 of the cover plate 41. Thus the bolt 1% isresiliently urged to turn in counter clockwise direction in FIG. 3. Thespring 24 may be positioned between the hanger plate 14 and cover plate41 as is clearly seen in FIG. 4, so that there is no need to provide aspace for only the said spring. In addition, when the latch bolt 18 iscaused to rotate about the shaft 16 in the clockwise direction in FIG. 6by engagement with the striker 10, the coil spring 24 will be expandedaround and along the shaft 16. Thus the exerting force of the spring 24on the bolt 18 is proportional to the rotated amount of the bolt, sothat an operating person can easily feel the door closing degree.

The shaft 16 comprises an enlarged portion 16a adapted for engagementwith the striker pin 12, whereby the lowering of the door relative tothe stationary member of the vehicle will be prevented. It will beapparent that any suitable collar may be fitted around the shaft 16 inplace of the enlarged portion A further coil spring 39 is mounted on theshaft 17. One end of the spring 39 is kept in engagement with an inwardprojection 40 of the pawl 19 so as to urge the pawl 19 to turn inclockwise direction in FIG. 3 whilst its other end is kept in engagementwith a slot of the cover plate (not shown). There is provided anelongated slot 42 on the cover plate 41. Within the elongated slot 42the projection 40 is movably fitted thereby limiting the movable rangethereof.

A rotatable striker-pressing member 27 made from a plastics material ismounted on the shaft 17 coaxially with the pawl 19. The striker-pressingmember 27 comprises a free end 28 one face of which is adapted forengagement with the striker pin 12, the other face being provided with aresilient member 29 secured thereto and preferably made from a rubbermaterial. The numeral 30 denotes an outwardly projecting flange orabutment the cover plate 41 which is engageable with the resilientmember 29 as a stopper when the door is in its fully latched position asis seen in FIG. 3. It should be noted that the resilient member 29 maybe secured to the stopper flange 30 in place of the pressing memher 27.The numeral 43 denotes a resilient stopper for prevention of excessturning of the latch bolt 18 in the counter clockwise direction in FIG.6.

Referring to FIG. 9, a modification of the strikerpressing member isillustrated. This modified pressing member 127 is engageable resilientlywith the rubber member 129 which is securely attached to the hangerplate 115. When the striker engages the latch bolt 118 in its fullylatched position, the pressing member 127 is urged to press resilientlyagainst the striker by means of the rubber member 129.

The engaging point of the striker 10 and latch bolt 18 is positioned inthe same plane as the engaging point of the pawl 19 and latch bolt 18 asis seen in FIG. 4. By virtue of this construction, no twisting forcewill be applied to the pawl 19 when the latch bolt 18 is urged todisengage with the striker pin 12 due to the laterally acting force.Thus the engagement of the pawl 19 with the bolt 18 may be maintained insafety.

Then, referring to FIGS. 5 and 8, the numeral 31 indicates a lockinglever which is pivotally mounted on an end portion 32 of the shaft 17.One end 31a of the locking lever 31 is operatively connected to aninside locking button (not shown) while its other end 31b is operativelyconnected to an outside key cylinder (again not shown).

Open lever 33 is pivoted on a pin 34 studded on the cover plate 41. Dueend 33a of the open lever 33 is operatively connected to an inside openhandle (not shown) through an inside open lever 37 whilst its other end3312 is operatively connected to an outside door handle (again notshown). An intermediate lever 35 is pivotally mounted on the open le er33 at a pivot pin 36.

A cancelling lever 38 connected to the pawl 19 through its projection 40secured to the lever 38 and provided with two projecting flanges 38a and33b is pivotally mounted on the end portion 32 of the shaft 17 coaxiallywith the locking lever 31. When the locking lever 31 is positioned inthe unlocking position as in FIG. 8, the rocking operation of the openlever 33 about the pivot 34 will be transmitted to the cancelling lever38 at the flange 3Sb thereby permitting the cancelling lever 38 torotate in the clockwise direction to allow disengagement of the pawl 19and latch bolt 18. When the locking lever 31 is positioned in thelocking position, the intermediate lever 35 is rotated in the clockwisedirection in FIG. 8 by rotation of the locking lever 31 so that therocking action of the open lever 33 results in an idle movement.

In operation, the door latch mechanism 13 fixed on the door advances inthe direction from left to right in FIG. 3, the striker pin 12 isbrought into engagement with the latch bolt 18 at its recess 20 which isthus caused to rotate in the clockwise direction in FIG. 3 against theexerting force of the spring 24. By this actuation, the front edge offirst ratchet tooth 21 on the bolt 18 is brought into engagement withthe tooth 23 of the pawl 19 which is thus rotated in the counterclockwise direction against the urging force exerted by the coil spring39. In this way, the ratchet tooth 21 is brought into contact with thepawl member 1) so that the door latch mechanism is maintained in itssecondary latched position.

With further continuation of the door advancement in its closingdirection, the front edge of second ratchet tooth 22 will actuate thepawl 19 for further rotation and finally the tooth 22 is brought intomeshing with the pawl, thus the desired fully latched position of thelatch mechanism is attained, It should be noted that during thisoperation the enlarged portion 16a of the shaft 16 is negligiblyaffected by the striker pin 12. When the latch mechanism is in its fullylatched position, the enlarged shaft 16a is rigidly contacted with andslightly lifted by the striker pin 12 thereby preventing the lowering ofthe door with respect to the stationary member of the vehicle.Meanwhile, the striker pin 12 causes the striker-pressing member 27 (or127) to resiliently press on the stopper 30 through the resilient member29 (or 129). The resilient force exerted by the member 29 (or 129) willallow the rocking of pressing member 27 (or 127) between the striker pin12 and stopper 30 (or hanger plate in dependence upon bumping of thevehicle so as to prevent the noise and rattles of the latch mechanism.

In addition. the striker pin 12 is engaged with the bolt 18 in the sameplane in which the pawl 19 is engaged with the latter as is clearly seenin FIG. 4, whereby objectionable force to cause the pawl 19 to disengagewith the latch bolt 18 is not applied to the pawl 19 even when the heavylaterally acting force is applied to the vehicle.

When the door is closed, keeping the locking lever 31 in its lockingposition, the latch bolt 18 is caused to rotate the pawl 19 in thecounter clockwise direction in FIG. 3 whereby the cancelling lever 38connected to the pawl 19 through the. projecting pin 40 is rotated inthe clockwise direction to strike the intermediate lever 35. When theintermediate lever 35 is swung about the pivot 36 in the counterclockwise direction, the locking lever 31 is shifted to its unlockingposition. Thus the lock cancelling operation is accomplished.

When it is desired to perform the keyless lock operation, it is onlynecessary to close the door by the outside door handle being held in itsdoor opening position while keeping the inside door lock button in itslocking position. While the latch bolt 18 is being brought into itsfully latched position by engagement with the striker 10, the projection38a of the cancelling lever 38 can not strike the intermediate lever 35so that the door latch mechanism 13 is kept in its locked positionwithout use of the door key.

What is claimed is:

l. A door latching mechanism comprising,

a base plate including a hanger plate and affixed to the door,

a cover plate fixed to said base plate opposite to said hanger platewith respect to said base plate and provided with an elongated slot,

a first shaft rigidly mounted on and between said hanger plate and saidcover plate,

a latch bolt in the form of a rotatable fork pivotally mounted on saidfirst shaft and adapted for engagement with a striker pin,

a second shaft rigidly mounted on and between said hanger plate and saidcover plate substantially in parallel relationship with said firstshaft,

a pawl pivotally mounted on said second shaft to retain the engagementof said latch bolt and striker said pawl being provided with a pinmounted for movement in said elongated slot, and

a cancelling lever mounted coaxially with said pawl and fixed to saidpin for moving said pawl to release the engagement of said latch boltand striker pin.

2. A door latching mechanism as claimed in claim 1 and furthercomprising,

an open lever,

an intermediate lever operatively connected with said open lever,

said cancelling lever being provided with a first projecting flange forengagement by said intermediate lever when said open lever is actuated,whereby said pawl is released from said latch bolt.

3. A door latching mechanism as claimed in claim 2 wherein saidcancelling lever has an L-shaped configuration, said first projectingflange being on one arm thereof and is further provided with a secondprojecting flange on the other arm thereof for engagement with saidintermediate lever when said cancelling lever is actuated by said pawl,and further comprising a locking lever operatively connected to saidintermediate lever whereby said intermediate lever is moved to preventengagement with said first projecting flange of the cancelling leverwhen said locking lever is actuated.

4. A door latching mechanism as claimed in claim 3 wherein said lockinglever is mounted coaxially with said cancelling lever.

5. A door latching mechanism as claimed in claim 3 wherein said lockinglever and cancelling lever are mounted on said second shaft.

1. A door latching mechanism comprising, a base plate including a hangerplate and affixed to the door, a cover plate fixed to said base plateopposite to said hanger plate with respect to said base plate andprovided with an elongated slot, a first shaft rigidly mounted on andbetween said hanger plate and said cover plate, a latch bolt in the formof a rotatable fork pivotally mounted on said first shaft and adaptedfor engagement with a striker pin, a second shaft rigidly mounted on andbetween said hanger plate and said cover plate subsTantially in parallelrelationship with said first shaft, a pawl pivotally mounted on saidsecond shaft to retain the engagement of said latch bolt and strikerpin, said pawl being provided with a pin mounted for movement in saidelongated slot, and a cancelling lever mounted coaxially with said pawland fixed to said pin for moving said pawl to release the engagement ofsaid latch bolt and striker pin.
 2. A door latching mechanism as claimedin claim 1 and further comprising, an open lever, an intermediate leveroperatively connected with said open lever, said cancelling lever beingprovided with a first projecting flange for engagement by saidintermediate lever when said open lever is actuated, whereby said pawlis released from said latch bolt.
 3. A door latching mechanism asclaimed in claim 2 wherein said cancelling lever has an L-shapedconfiguration, said first projecting flange being on one arm thereof andis further provided with a second projecting flange on the other armthereof for engagement with said intermediate lever when said cancellinglever is actuated by said pawl, and further comprising a locking leveroperatively connected to said intermediate lever whereby saidintermediate lever is moved to prevent engagement with said firstprojecting flange of the cancelling lever when said locking lever isactuated.
 4. A door latching mechanism as claimed in claim 3 whereinsaid locking lever is mounted coaxially with said cancelling lever.
 5. Adoor latching mechanism as claimed in claim 3 wherein said locking leverand cancelling lever are mounted on said second shaft.